Dental unit construction

ABSTRACT

A dental unit which may be located adjacent a dental chair, including a compact, floor mounted cabinet with a dental tray assembly pivotally mounted thereon by a conventional adjustable tray arm. The tray assembly includes a hollow support platform and a removable tray portion. A plurality of usual dental handpieces and a syringe are supported upon the support platform, electrical, air and water connections therefore being mounted therein, and normally concealed by the removable tray portion. A control box therefor is mounted on the support platform. Water and air control and electrical control panels are hingedly mounted in the cabinet, adapted to be closed and concealed when not in use, a pilot light is mounted on the cabinet and front and side doors mounted thereon providing access to the instrument supply and regulation equipment located therein.

United States Patent Buchtel et al.

[54] DENTAL UNIT CONSTRUCTION [52] US. Cl ..32/22 [51] Int. Cl ..A6lc 19/02 [58] Field of Search ..32/22, 23, 24, 25; 248/279,

[56] References Cited UNITED STATES PATENTS 3,455,620 7/1969 Coburn ..32/22 3,524,256 8/1970 Barker ..32/22 [4511 Sept. 19, 1972 Primary Examiner-Robert Peshock Attorney-J0hn H. Bishop et al.

[ 5 7] ABSTRACT A dental unit which may be located adjacent a dental chair, including a compact, floor mounted cabinet with a dental tray assembly pivotally mounted thereon by a conventional adjustable tray arm. The tray assembly includes a hollow support platform and a removable tray portion. A plurality of usual dental handpieces and a syringe are supported upon the support platform, electrical, air and water connections therefore being mounted therein, and normally concealed by the removable tray portion. A control box therefor is mounted on the support platform. Water and air control and electrical control panels are hingedly mounted in the cabinet, adapted to be closed and concealed when not in use, a pilot light is mounted on the cabinet and front and side doors mounted thereon providing access to the instrument supply and regulation equipment located therein.

11 Claims, 13 Drawing Figures mzau P'AIE'N'TE'Dsma m2 3.691.634

SHEEI1I1F4 a 5 s 24 T I3. f-LTMS DEAN HBUCH I EL. KENNETH R. LAPPIN 8. BY JOHN A. MAURER ATTORNEY PATENTED EP 1 12 3.691. 634

sum 2 or 4 FIG. 3 0

INVEN TUHS DEAN H. BUCHTEL.

B Y JOHN A. MAURER wxk W ATTORNEY KENNETH R. LAPPIN 8. I

PATENTEBsEPIQ m2 $691,634

sum 3 or 4 Ixw; 7' 01:5 DEAN H. BUCHTEL, KENNETH R. LAPPIN& BY JOHN A. MAURER i; {7W 4% 64M ATTORNEY FIG.|3

SHEET k [If 4 PATENTEDsrr 19 m2 [\"VENTUHS DEAN H. BUCHTEL. KENNETH R. LAPPIN & BY JOHN A. MAURER ATTORNEY FIG.

DENTAL UNIT CONSTRUCTION CROSS-REFERENCES TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION 1 Field of the Invention The invention relates to dental unit constructions and more particularly to a generally floor mounted cabinet located near a dental chain and patient in which dental instruments and the controls therefor are contained and concealed within a single, compact and attractive cabinet. A movable dental tray, pivotally connected with the cabinet by a tray arm, supports dental handpieces, syringe, and various equipment controls providing flexibility in a dentists working position and equipment control, for either a rightor a lefthanded dentist.

2. Description of the Prior Art Prior dental units normally have included usual cup holder assemblies, instrument holder assemblies, and pivotally mounted trays, each separately mounted on a cabinet or stand located beside the usual dental chair.

Furthermore, the controls for these various accessories and assemblies, including the supply and regulatory controls for the dental instruments, usually have been mounted on the cabinet or stand, partially exposed, for ease of maintenance and use, resulting in a cluttered and unattractive appearance. The other alternative has been to conceal these controls and equipment within a cabinet making adjustments and maintenance extremely difficult.

The trend today is to provide dental equipment which is aesthetically attractive and compatible with modern office decor, and at the same time permit efficient and convenient use of the equipment in performing dental work. This necessitates concealment of instruments and associated controls when not in use, while providing easy accessibility when needed. Likewise, the required equipment, plumbing and power supply means should be unexposed yet accessible for ease of maintenance.

Some dental instruments in other prior units have been located on the tray assembly for easy accessibility by the dentist, and remaining equipment and instruments have been located on a base unit. Such tray assembly is bulky anddifficult to maneuver and requires the dentist to use the tray handpieces at all times even when his working position is adjacent the base unit.

Likewise, these arrangements require the dentist to continually reposition himself for manipulating the various equipment and controls, part of which are on the base unit and part of which are on the tray assembly. All of this has been inconvenient for the dentist, many times interrupting his dental work, and has been disturbing to the patient.

Thus, a need has existed for an attractive dental unit in which the various dental equipment and associated controls can be concealed when not in use, in which the instrument supply and regulation means are concealed yet readily accessible for maintenance, and in which certain dental handpieces and their controls are located on the dental tray and within the dental cabinet.

SUMMARY OF THE INVENTION Objectives of the invention include providing an improved dental unit construction including a cabinet in which the handpiece accessories and controls therefor are mounted on retractable hinged panels in the dental cabinet; providing a dental unit in which the instrument supply and regulation means are completely concealed within the cabinet but are easily accessible for maintenance, adjustment and repair; providing a dental unit having improved waste drain means which occupies less space within the cabinet and. which carries waste water 0K in a most expedious manner; provided a dental unit having an adjustable tray arm mounted thereon and carrying a tray for positioning the needed dental supplies and accessory tools conveniently adjacent the dentist, dental assistant and patient; providing a dental unit including a tray comprising a hollow support platform containing the electrical air and water connections for the components: on the tray and a removable tray portion normally concealing said connections; providing a dental unit in which various dental handpieces and equipment control switches are supported on the dental tray for the convenience and ease of their use; providing a dental unit that can be used equally as well by a rightor left-handed dentist; providing a dental unit having a high vacuum connection for the saliva ejector, referred to herein as an airvac unit; providing a dental unit having front and side doors thereon providing access to and normally concealing instrument supply and regulation equipment located therein; providing a dental unit including a cabinet with a pilot light thereon; providing a dental unit having the foregoing advantageous features in a compact, aesthetically pleasing, yet easily accessible and serviceable assembly; and providing a dental unit construction which satisfies the stated objectives, and which avoids difficulties heretofore encountered in a simple, effective manner, and which solves problems and satisfies existing needs in the art.

These objectives and advantages are obtained by the dental unit construction, the general nature of which may be stated as including a generally rectangular cabinet formed by a back wall, a top wall, and front and side walls having hinged doors therein, the front wall having an upper and a lower portion; the upper front wall portion comprising a central fold away cover for a drinking cup support, a hingedly mounted water and air control panel on one side thereof and a hingedly mounted electrical control panel on the other side thereof; air, water and electrical supply and regulation means located within the cabinet; knobs and switch buttons on the inner sides of said control panels for controlling said air, water and electrical supply and regulation means; a horizontally disposed hinged middle door separating the front wall upper and lower portions and enclosing a plurality of knobs for adjusting the volume of water supplied to the handpiece coolant system, for adjusting the drive air supplied to the handpiece,'for controlling the volume of water supplied to the saliva ejector pumps and for adjusting the air regulator for air coolant supplied to the handpieces; high volume saliva ejector means located within the cabinet and including pump means mounted on the inside surface of one of the side wall doors and having a hose and nozzle connected therewith and removably supported on the outer surface of said door; a horizontally hinged lower door forming the lower front wall portion extending from said middle door to the bottom of the cabinet and providing access to the interior of the cabinet; a drain standpipe assembly within the cabinet comprising a main'tube for carrying off high volume waste water and a plurality of lateral drain connections including connections to the instrument supply and regulation means and to the drinking cup support; a tray assembly including a pivotally adjustable tray arm connected to the top of the cabinet, a hollow support platform removably supporting dental handpieces, and a syringe, and electrical, air and water connections therefor carried by said tray arm, and a removable tray portion normally concealing said connections; and a pilot light upon the top of the cabinet; said fold away cover, control panels and middle and lower doors when in closed position forming a substantially flush unobstructed front wall for the cabinet.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the invention illustrative of the best mode in which applicants have contemplated applying the principles is set forth in the following description and shown in the accompanying drawings, and is particularly and distinctly pointed out and set forth in the appended claims.

FIG. 1 is a perspective view of the improved dental unit construction with the tray arm in partially extended position;

FIG. 2 is a front elevation of the dental unit cabinet with portions broken away;

- FIG. 3 is a right-hand side elevation of the cabinet shown in FIG. 2 with portions broken away;

FIG. 4 is a left-hand side elevation of the cabinet shown in FIG. 2 with the front access door and panels shown in open position;

. FIG. 5 is an enlarged fragmentary top plan view looking in the direction of the arrows 5-5, FIG. 4;

FIG. 6 is a fragmentary front elevation similar to FIG. 2 with portions broken away and the side cabinet door in open position;

FIG. 7 is an enlarged fragmentary front elevation with portions broken away showing the dental unit main supply lines and waste line terminal connections;

FIG. 8 is an enlarged sectional view taken on the line 88, FIG. 1 showing the dental tray control box;

FIG. 9 is a top plan view looking in the direction of the arrows 9-9, FIG. 8;

FIG. 10 is a top plan view of the dental unit waste standpipe assembly;

FIG. 11 is an elevational view looking in the direction of the arrows 111l, FIG. 10;

FIG. 12 is a perspective view of the tray with the removable portion removed to permit access to the electrical air and water connections for the various components mounted on the tray; and

FIG. 13 is a detached perspective view of the removable portion of the tray.

DESCRIPTION OF THE PREFERRED EMBODIMENT The improved dental unit construction of the present invention is indicated generally at l and includes an upper generally rectangular cabinet 2 supported on a lower housing 3. Cabinet 2 consists of back wall 5, side walls 6 and 7, and a top wall 8. A usual pivotal tray arm 9 is mounted on and extends outward from top wall 8.

The front wall of cabinet 2 is composed of a series of doors and includes a lower hingedly mounted door 10, which when opened exposes and provides easy access to the internally contained instrument supply and regulation means 11. A middle horizontally extending door 12 is hingedly mounted at its lower edge and located above the top of door 10 to provide access to control knobs 13-20 mounted therebehind.

The knobs 13, 14 and 15 are water spray adjustment valves to adjust the volume of water supplied to the handpiece coolant system for the three handpieces 61 shown in FIGS. 1 and 12. The knobs 16, 17 and 18 are provided to adjust or regulate the drive air supplied to the three handpieces 61.

The knob 19 provides adjustment of the air regulator for the air coolant supplied to all three of the handpieces 61. The knob 20 is the metering valve controlling the volume of water supplied to the saliva ejector pump to be later described.

The upper front wall portion of the cabinet 2 includes a water and air control panel 21 and an electrical control panel 22, both pivotally recess mounted at their lower ends, at the righthand side and left-hand side, respectively, of the fold away cover 23 concealing a drinking cup support 4 (FIG. 6). A unit power-on indicating pilot light 24 is mounted at the top of cabinet Side wall 7 (FIG. 3) includes a door 25 hingedly mounted at 26 along one vertical edge thereof providing access into cabinet 2 for maintenance and adjustment of saliva ejector hose control mechanism, and hot water tank thermostat and solenoid valves.

Power supply receptacles 27 and auxiliary supply line openings covered by a plug 28 may be provided in lower housing side walls 29 below cabinet sidewalls 6 and 7. Receptacles 27 provide convenient power supply connections for any temporary equipment for which a dentist may have a need. Likewise, plug 28 may be conveniently removed from the openings in one side or the other of the lower housing side walls 29 to insert a supply tube 28a for a foot controller 28b and junction box 28c.

The supply tube 28a foot controller 28b and junction box 28c, plugged into unit 1 for a right-hand dentist are shown in FIGS. 1, 2 and 3. FIG. 1 also shows the supply tube 28a, foot controller 28b and junction box 28c in dot-dash lines for a left-handed dentist.

Panel 21 (FIG. 5) may include metering valves 30 and 31 for regulating a fixed or portable dental bowl not shown herein but disclosed and claimed in a companion application, and a metering valve 32 for regulating the water volume supplied to a drinking cup 4' located behind fold away cover 23.

A saliva ejector hose 33 connected to usual saliva ejector pump means 34 (FIG. 3) within cabinet 2 may extend through the center of panel 21 for connection of a usual saliva ejector mouthpiece.

Three quick connect outlets 35, 36 and 37 also may be located on panel 2 and connected with suitable supply lines within cabinet 2. Outlets 35 and 36 may be connected to water supply lines with outlet 37 connected to an air supply line. These may be used by a dentist for attachment of a special tool, instrument or accessory, such as any air or water syringe or a hydro colloid attachment.

Panel 22 includes a number of control buttons 38-42 for actuating certain switches, and the buttons preferably are lighted when actuated. Button 38 may be for a master power switch controlling the incoming power supply for the entire dental unit 1 which when actuated also energizes indicating pilot light 24. Button 39 may be an on-off switch for a water heater mounted within cabinet 2, button 40 may control saliva ejector pump 34, button 41 may control a water and vacuum solenoid for a dental bowl, and button 42 may actuate a time delay switch which regulates the cold water flow time for filling the dental unit drinking cup 4'. A fuse 43 for the entire dental unit electrical system may also be located in panel 22.

Side wall 6 (FIG. 4) includes a door 44 hingedly mounted at 440, which when opened provides access into cabinet 2 for maintenance of bowl vacuum pump and solids collector (not shown). A usual high volume air-vac saliva ejector unit 45 may be mounted on the inside surface of door 44 (FIG. 6) with an ejector hose 46 extending downward along the outside of door 44. Airvac unit 45 is normally used by a dental assistant during procedures that cannot be taken care of by saliva ejector pump means 34.

A saliva nozzle 47 (FIG. 4) is supported on a bracket 48 which extends through door 44 and is pivotally connected with a switch 49 (FIG. 6) mounted on the inside of door 44. A control air line 50 (FIG. 6) extends between switch 49 and ejector unit 45 whereby the removal of nozzle 47 frombracket 48 actuates switch 49 energizing ejector unit 45.

The air supply line 51 for air-vac unit 45 is connected to an air vacuum solenoid and regulator 52 for adjusting the suction pressure of unit 45. A drain hose 54 connects unit 45 with a main waste standpipe assembly 55.

A tray unit 56 is connected to the swinging end of tray arm 9 in a customary manner, and includes a hollow support platform 58 formed with an open center area 58' into which a removable tray 59 may be recess mounted. A water syringe 60 may be removably supported on either side of platform 58, with three various dental handpieces 61 removably supported on either platform side. FIG. 1 shows the normal arrangement of these components for a right-handed dentist.

l-landpieces 61 are the usual dental instruments for high or low speed cutting or drilling operations requiring a supply of air of water, or a combination of air and water for either driving power, cooling purposes or both.

Syringe 60 likewise requires a supply of air and water for proper operation. None of the particular syringe 60 and dental handpieces 61 are critical to the principles of the present invention other than in the general combination shown. Any other handpieces or syringes could be substituted without departing from the broad principles of the present invention. A usual gas supplied bunsen burner 62 also may be mounted on and extend upward from a rear corner of platform 58 with a gas metering knob 63 for burner 62 attached to the rear edge of the platform (FIG. 9).

A dental tray control box 64 (FIGS. 1, 9 an 12) is mounted on the rear of platform 58 and contains an air supply gauge 65 and a series of control buttons which preferably are lighted when actuated. Button 66 may be for saliva pump means 34 duplicating the function of control panel button 40; button 66a for a dental bowl duplicating the function of control panel button 41; button 66b for adding warm water to the drinking cup; button 66c for energizing air-vac unit 45; and button 66d for energizing a lower voltage switch (not shown) for initiating a signal, audio or visual, to summon a dental assistant.

Within the hollow interior of the tray platform 58 are located electrical connection 92 and air and water connections indicated generally at 93, for the various components mounted upon the tray. As shown in FIG. 12, the removable tray 59 may be removed to expose these connections for the purpose of repairs and adjustments thereto or replacement thereof.

The location of the various control buttons and handpieces on tray unit 56 eliminates the dentist having to maintain a position close to unit 1 or else in many situations having to reach across the patient to actuate a control button or retrieve or return a handpiece to unit 1 which is both inconvenient for the dentist as well as being disturbing to the patient.

Likewise, when the dentist is working adjacent to dental unit 1, tray unit 56 can be pivoted easily to a convenient position from which the dentist may work or else moved out of the way. Thus, control panels 21 and 22 and dental tray control box 64 permit convenience of operation for the dentist at various working positions around the patient and the dental unit.

The control knobs 13-20, concealed by middle door 12, preferably are for various adjustments or controls which require little attention or change once the initial setting has been made. These adjustment and control knobs are conveniently located for easy accessibility yet are concealed behind a decorative door 12 enabling dental unit 1 to maintain an attractive and uncluttered appearance.

The plumbing and main supply line terminals for dental unit 1 preferably terminate near the bottom of cabinet 2 (FIG. 7) and may be aligned and mounted on and extend through a partition support member 67 into lower housing 3 for connection to incoming supply lines (not shown). The usual supply lines include a main water supply line having terminal 68 for water for the handpiece cooling systems, drinking cup supply, bowl member and for other accessories. A main gas supply line terminal 69 is provided for gas for burner 62 for heating of certain materials used by the dentist. An air supply line terminal 70 is provided for pressurized air for all component parts using air for their desired function.

Manual shutoff valves 71, 72 and 73 are provided for water line 68, gas line 69 and air line 70, respectively,

so as to permit repairs to any of the supply line laterals beyond the shutoff valves and also to provide a cutoff in case of power failure which might affect operation of solenoid operated valves or other components of ap paratus housed in cabinet 2.

Waste standpipe assembly 55 also may have a terminal mounted on support member 67 and may be attached thereto by a flange 74. The improved standpipe assembly 55 (FIGS. 10 and 11) reduces duplication of drain facilities within cabinet 2 permitting a more compact dental unit and better arrangement of components and enables high volume of water water to be quickly carried away in the most expeditious manner from all the components and devices housed in or supported by dental unit 1.

Standpipe 55 (FIGS. 10 and 11) is formed by a plurality of conduits 75 and T-coupling members 76 which join together various drain tube junction tees, forming a larger chamber surrounding the central tube 80 clear to the bottom of the standpipe. The high volume of waste water from saliva ejector 34 enters an elbow 79 at the top of standpipe 55 through saliva ejector delivery tube 77 which may be connected thereto by nut 78. Concentric central tube 80 communicates with ejector tube 77 and extends downward through standpipe 55 and carries the saliva ejector waste water to the bottom of standpipe 55 without interfering with any incoming laterals.

Another large volume of waste water may come from a dental bowl deliver tube 81 which is connected to a section of conduit 82. Conduit 82 extends downward into a reducer T-coupling 83, beyond the air-vac unit discharge hose connection 84 which is part of T- coupling 83. The pressure exerted by the dental bowl vacuum pump discharge water helps pull water from air-vac unit 45 through hose 54 and hose connection 84 into a common discharge elbow 85 from which the combined waste waters empty into the bottom of standpipe 55 adjacent the end of tube 80 for discharge into an outlet drain 86.

Various other drain tubes such as drain tube 86 from an overflow funnel for an equipment vacuum breaker and tube-87 from a drinking cup drain (FIG. 6) connect into standpipe 55 at various points by tees 88 and 89, respectively, which form part of standpipe 55. The waste water from tubes 86 and 87 discharge into the area of standpipe 55 which surrounds central tube 80 thereby not interfering with the high volume saliva ejector waste water. A vent tube 90 is connected to standpipe 55 by a tee 91 and may curve outward and upward a distance into cabinet 2 before opening to the atmosphere within cabinet 2 for venting of standpipe 55.

When the dental unit is not in use, the control panels 21 and 22, fold away cover 23 and hinged doors l and 12 may all be closed, as in FIGS. 2 and 3, forming a flush, unobstructed front for the cabinet with no visible screw heads, etc.

The improved dental unit construction 1 has a number of advantageous features. Cabinet 2 is compact requiring a minimum of space within the dentists office yet concealing the instrument supply and regulation means 11 within the cabinet. Access is provided to the interior of cabinet 2 for maintenance, repair and adjustment of the supply and regulation means from both sides and front of cabinet 2 thereby facilitating such work by sufficiently exposing the equipment upon which the work is to be performed. This access is gained easily through pivotally opened doors 10, 25, and 44 which eliminate the removal of screw held panels or the like.

Retractable panels 21 and 22 enable various dental equipment to be actuated and regulated by controls conveniently located on cabinet 2, yet these controls, when not needed, are easily concealed within cabinet 2 eliminating a cluttered appearance. Likewise, quickconnect outlets 35, 36 and 37 in panel 21 provide easy access attachments for auxiliary dental handpieces. Control box 64 on tray unit 56 places selected equipment control buttons conveniently adjacent the dentists working position eliminating him having to reach across a patient or around the tray unit to reach such controls usually located on the cabinet.

Another advantage is the mounting of indicating pilot light 24 on cabinet 2 which light is connected to master on-off button 38, to enable a dentist or dental assistant to tell at a glance when unit 1 is de-energized eliminating the need to check each component and control individually upon leaving the office at night.

The adjustment knobs 13-19 for the dental handpieces are conveniently located on cabinet 2 for operation thereof, yet are easily concealed behind door 12 enhancing the appearance of cabinet 2.

Dental unit 1 is also provided with a usual high volume saliva ejector unit conveniently housed within cabinet 2 which is actuated by removal of nozzle 47 from its storage bracket 48 and may also be controlled by button 666 located on the dental tray, thus providing for dual control thereof depending upon the dentists location.

Another advantage is the location of the various dental handpieces 60 and 61 on tray unit 56 which places the handpieces adjacent the dentists working position which can be adjusted to various positions depending upon the particular type of dental work being done and to suit a particular dentists preference as to equipment location.

A further advantage is the use of the improved waste water standpipe assembly 55 which eliminates duplication of drain facilities for the various dental equipment thereby reducing the amount of space needed for such equipment within cabinet 2 and which carries waste water in the most expeditious manner from all the components or devices housed in or supported on unit 1.

An important advantage of improved unit 1 is that it can be used by a rightor left-handed dentist without change excepting to have the high vacuum hose 46 on the opposite side door 25. Accordingly, the improved construction achieves the objectives indicated and solves problems existing in the art.

In the foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed.

Moreover, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details shown or described.

Having now described the features, discoveries and principles of the invention, the manner in which the dental unit construction is constructed and used, the characteristics of the construction, and the advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts, and combinations, are set forth in the appended claims.

We claim:

1. A dental unit construction including a generally rectangular cabinet having a back wall, a top wall and front and side walls; the front wall of the cabinet com prising an upper front wall portion and a lower front wall portion divided by a horizontally disposed middle door; said upper front wall portion including hinged control panels extending from said middle door to said top wall, said lower portion comprising a lower door extending from said middle door to the bottom of the cabinet, and said control panels and doors when closed forming a flush, unobstructed front wall; instrument supply and regulation means including water, gas, air and electrical components located and mounted within the cabinet; high volume saliva ejector means located and mounted within the cabinet; hinged doors mounted upon said side walls, said side wall doors and said lower door providing access within the cabinet to said instrument supply and regulation means and to said high volume saliva ejector means; control knobs for said cabinet-housed supply and regulation means normally concealed by said middle door; means for controlling operation of said supply and regulation means on the inner sides of said control panels; a waste water drain standpipe communicating with said water components within the cabinet; a tray arm pivotally connected to the cabinet; a tray mounted upon said tray arm; and at least one handpiece and syringe means removably supported upon the tray.

2. A dental unit as defined in claim 11 in which the high volume saliva ejector means is mounted upon the inside of one of the side wall doors; and in which a hose connected to said saliva ejector means has a nozzle thereon and extends through an aperture in said side door and is supported on the outer side of said side door. 1

3. A dental unit as defined in claim 1 in which the standpipe includes a central tube extending within and open at its lower end within a larger tube, means communicating with the saliva ejector discharging waste water into said central tube, and means communicating with dental bowl and drinking cup drain means discharging waste water therefrom into said larger tube.

4. A dental unit as defined in claim 1 in which the tray comprises a hollow support platform and a removable tray portion.

5. A dental unit as defined in claim 4 in which connections for electrical, air and water components are mounted on the tray and are located within the hollow support platform; andin which dual control actuating buttons for said electrical, air and water components are mounted on said platform and on said control panels.

6. A dental unit as defined in claim 1 in which a pilot light is mounted on the exterior of the cabinet; and in which the pilot light is connected to and indicates enerti of d e tri n ts.

. A ilen unit s c irh ih cldim 1 in which drinking cup filler and waste water drain means are located within the cabinet between two spaced control panels; in which a fold-away cover conceals said drinking cup filler and waste water drain means; and in which the two spaced control panels and the fold-away cover form the upper front wall portion of the cabinet.

8. A dental unit as claimed in claim 1 in which the control panels are hinged on a horizontal axis at their lower ends and are removable between open and closed positions; in which control actuating buttons for the electrical, air and water components are mounted on the upper end of one of the control panels; and in which the buttons are accessible when the one control panel is in open position.

9. A dental unit as claimed in claim 8 in which there are two spaced hinged control panels, in which metering valve means for water components and a second saliva ejector connection are mounted on the upper end of the second control panel; and in which the metering valve means and the saliva ejector connection are accessible when the second control panel is in open position.

10. A dental unit as claimed in claim 1 in which a lateral partition support member is located in the cabinet; and in which terminal connections for main water supply, main gas supply, and air supply lines, and for said waste water standpipe are mounted on said support member in alignment.

11. A dental unit as claimed in claim 1 in which the standpipe includes a central tube extending within and open at its lower end within a larger tube forming a chamber between the tubes; in which the high volume saliva ejector means is connected to the upper end of the central tube; in which dental bowl drain means is connected to said chamber adjacent the lower end of the central tube; and in which drinking cup filler drain means, overflow vacuum breaker funnel means, and vent means are connected to the chamber intermediate the upper and lower ends of the central tube. 

1. A dental unit construction including a generally rectangular cabinet having a back wall, a top wall and front and siDe walls; the front wall of the cabinet comprising an upper front wall portion and a lower front wall portion divided by a horizontally disposed middle door; said upper front wall portion including hinged control panels extending from said middle door to said top wall, said lower portion comprising a lower door extending from said middle door to the bottom of the cabinet, and said control panels and doors when closed forming a flush, unobstructed front wall; instrument supply and regulation means including water, gas, air and electrical components located and mounted within the cabinet; high volume saliva ejector means located and mounted within the cabinet; hinged doors mounted upon said side walls, said side wall doors and said lower door providing access within the cabinet to said instrument supply and regulation means and to said high volume saliva ejector means; control knobs for said cabinet-housed supply and regulation means normally concealed by said middle door; means for controlling operation of said supply and regulation means on the inner sides of said control panels; a waste water drain standpipe communicating with said water components within the cabinet; a tray arm pivotally connected to the cabinet; a tray mounted upon said tray arm; and at least one handpiece and syringe means removably supported upon the tray.
 2. A dental unit as defined in claim 1 in which the high volume saliva ejector means is mounted upon the inside of one of the side wall doors; and in which a hose connected to said saliva ejector means has a nozzle thereon and extends through an aperture in said side door and is supported on the outer side of said side door.
 3. A dental unit as defined in claim 1 in which the standpipe includes a central tube extending within and open at its lower end within a larger tube, means communicating with the saliva ejector discharging waste water into said central tube, and means communicating with dental bowl and drinking cup drain means discharging waste water therefrom into said larger tube.
 4. A dental unit as defined in claim 1 in which the tray comprises a hollow support platform and a removable tray portion.
 5. A dental unit as defined in claim 4 in which connections for electrical, air and water components are mounted on the tray and are located within the hollow support platform; and in which dual control actuating buttons for said electrical, air and water components are mounted on said platform and on said control panels.
 6. A dental unit as defined in claim 1 in which a pilot light is mounted on the exterior of the cabinet; and in which the pilot light is connected to and indicates energization of said electrical components.
 7. A dental unit as claimed in claim 1 in which drinking cup filler and waste water drain means are located within the cabinet between two spaced control panels; in which a fold-away cover conceals said drinking cup filler and waste water drain means; and in which the two spaced control panels and the fold-away cover form the upper front wall portion of the cabinet.
 8. A dental unit as claimed in claim 1 in which the control panels are hinged on a horizontal axis at their lower ends and are removable between open and closed positions; in which control actuating buttons for the electrical, air and water components are mounted on the upper end of one of the control panels; and in which the buttons are accessible when the one control panel is in open position.
 9. A dental unit as claimed in claim 8 in which there are two spaced hinged control panels, in which metering valve means for water components and a second saliva ejector connection are mounted on the upper end of the second control panel; and in which the metering valve means and the saliva ejector connection are accessible when the second control panel is in open position.
 10. A dental unit as claimed in claim 1 in which a lateral partition support member is located in the cabinet; and in which terminal connections for main water supply, main gas suppLy, and air supply lines, and for said waste water standpipe are mounted on said support member in alignment.
 11. A dental unit as claimed in claim 1 in which the standpipe includes a central tube extending within and open at its lower end within a larger tube forming a chamber between the tubes; in which the high volume saliva ejector means is connected to the upper end of the central tube; in which dental bowl drain means is connected to said chamber adjacent the lower end of the central tube; and in which drinking cup filler drain means, overflow vacuum breaker funnel means, and vent means are connected to the chamber intermediate the upper and lower ends of the central tube. 